The present invention relates to protective headgear or helmets including optical systems to enable the wearer to see an image of the view to the rear of the wearer.
The need for such optical systems arises because protective headgear gives protection to the head from impact during an accident but its inherent bulk and weight reduces the wearer's awareness of the surroundings by restricting the field of vision and as importantly, by decreasing the ease with which the wearer can scan the view to the rear and to the sides.
This lack of awareness can be a problem when a helmet is worn by people engaged in a security role but it is particularly important when the helmet is worn by drivers of vehicles such as motorcycles. Improving the motorcyclist's awareness of the situation to the rear is a significant safety factor.
Previous patents, such as the British Pat. Nos. 2,057,159 A and 2,077,942 A have described optical systems which are too large and/or have fields of view which are too restricted for them to be of serious practical value, particularly to motorcyclists. It is an object of the present invention to overcome these limitations by achieving a good field of view to the rear of the wearer, giving an image of suitable size and quality, whilst keeping the device in a compact and practical form.